BACKGROUND AND OBJECTIVES: Most cases of sudden deafness remain idiopathic. The majority of these cases are unilateral in their occurrences, whereas bilateral simultaneous involvement is rarely seen. We analyzed the clinical characteristics and treatment results between bilateral and unilateral sudden sensorineural hearing loss (SSNHL), and considered the possible causes and provided available data for planning the appropriate treatment for bilateral SSNHL.
SUBJECTS AND METHOD: Three hundred forty seven patients who visited the Department of Otolaryngology in Ajou University Hospital from June, 1994 to February, 2003 were classified into 3 groups. Of these 347 patients, 16 patients (32 ears) had SSNHL simultaneously in both ears (Group I), 23 patients had SSNHL sequentially in both ears (Group II), and 308 patients had unilateral SSNHL (Group III). We reviewed their charts for pure tone audiometry information, medical history and lipid panel information to compare bilateral SSNHL with unilateral SSNHL.
RESULTS: The incidence of simultaneous bilateral SSNHL (Group I) was 4.6% of overall patients with SSNHL. Bilateral SSNHL occurs more commonly in patients of older age, with preexisting DM. Lpid panel abnormalities were compared with unilateral SSNHL. The recovery rate of hearing in simultaneous bilateral SSNHL (Group I) was 37.5% for both ears and 62.5% of patients, compared with 56.5% in unilateral SSNHL (Group III).
CONCLUSION: Bilateral SSNHL is a very rare disease and the outcome from treatment is important for patients' quality of life. Recognition of similarities and differences between bilateral and unilateral SSNHL can help in counseling and managing the patients.